[en] We review the chemical ecology of the ladybird beetle Harmonia axyridis from the perspective of its invasiveness and the deleterious effects it exerts in the regions it has colonised. We outline the nature and quantification of its chemical defence, and discuss the protection this provides from natural enemies, particularly intraguild predators. We consider the role played by infochemicals in location of prey, intraspecific communication and intraguild interactions; we also discuss the role of prey allelochemicals in relation to H. axyridis extreme dietary generalism. Harmonia axyridis poses a number of practical problems for human health and well-being, including “lady beetle taint” wine contamination and problems consequent on large aggregations overwintering in buildings. We discuss chemical insights into these issues and, in particular, how attractants and repellents might help manage H. axyridis populations. We conclude by discussing future perspectives for research.